1. Field of the Invention
The present invention relates to a transfer type inkjet recording method.
2. Description of the Related Art
As one of printing methods, a recording method (transfer type inkjet recording method) is mentioned which includes forming an intermediate image on an intermediate transfer body by an inkjet recording method, and transferring the intermediate image to a recording medium to form a final image. In the transfer type inkjet recording method, a method is known which includes giving an aggregation liquid which aggregates inks to an intermediate transfer body in order to increase image performance and water resistance (Japanese Patent Laid-Open No. 2003-246135). The method described in Japanese Patent Laid-Open No. 2003-246135 aggregates the inks on the intermediate transfer body with an aggregation liquid containing a cationic polymer, such as dicyandiamide resin or polyallylamine to suppress bleeding (mixture of colors of inks) to thereby increase image performance. Furthermore, by increasing the molecular weight of cationic substances, the film strength of images is increased to thereby increase the water resistance.
However, according to an examination of the present inventors, the recording method described in Japanese Patent Laid-Open No. 2003-246135 has the following problems. First, there is a problem in that the transfer properties in transferring the intermediate image on the intermediate transfer body to a recording medium are not good and the final image formed on the recording medium is distorted. This is considered to be because the aggregation properties of inks forming the intermediate image are insufficient when the printing Duty is high, so that the internal aggregation force of the intermediate image required for transferring becomes insufficient. Such a reduction in the transfer properties is particularly remarkable when a fine quality paper having relatively high surface roughness or the like is used as the recording medium.
Furthermore, there is a problem in that scratch resistances when moisture is given to printed substances which are required in commercial printed substances and the like are insufficient. The commercial printed substances are left as they are in a state where water adheres onto the printed substances, and then used after removing the water in some cases. The scratch in such a state where moisture is given thereto is referred to as “wet scratch”. When the printed substances obtained by the recording method described in Japanese Patent Laid-Open No. 2003-246135 have been subjected to the wet scratch, scratch marks are generated on the images to cause considerable distortion in some cases. This is considered to occur due to the fact that when water is left on the printed substances on which images are formed, the water permeates into the printed surface so that the printed surface is swollen to be deteriorated, and then water wiping is performed in such a state, resulting in the separation of the swollen printed surface.
In the case where the inks are color inks, bleeding has sometimes occurred when high concentration images having a high printing Duty have been formed. This is considered to be because the aggregation force is not sufficient when a component which aggregates the ink is only a cationic polymer (aggregation agent), and when the ink amount is large relative to the amount of the aggregation liquid per unit area, it becomes difficult to sufficiently aggregate the inks forming the intermediate image.